The formula H2O is also the molecular formula of water. For non-molecular substances such as table salt, we represent the composition with an empirical formula. Sodium chloride is represented by NaCl, meaning that sodium and chlorine ratio in sodium chloride is 1 to 1. Again, the subscript 1 is omitted.
By Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.Segmentation is also called metamerism.y Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.
[werm] 1. any of the soft-bodied, elongated, naked invertebrates of the phyla annelida, acanthocephala, aschelminthes, and platyhelminthes; called also vermis. Worms are often found as parasites in humans and other animals; in North America the most common of these are roundworms and tapeworms. flukes are a serious problem in other parts of the world. Most worm infections are transmitted from person to person via feces that contaminate food and water.